OCI Lib utilise le plug-in 4D for OCI to replicate 4D for Oracle calls and behaviour. Conversion of an existing database using 4D for Oracle to 4D for OCI is quick and transparent (no need to rewrite any code).
OCI Lib is available for 4D 2004.
(Source code is available)

oEd Explorer provides a replacement for the native Explorer in the Design Environment. oEd Explorer organizes all methods, including database methods, project methods, form methods and object methods, into a fully hierarchical display for easier access.

Postcode Anywhere Webservices SOAP Client is a 4D component which allows users to find out and complete addresses from within the 4D application. It is available as a 4D component for free. Source code is also available separately.
(Source code is available)